The game field consists of squares. Each square has its respective field coordinate represented by a unique number. On the 10×10 field, the squares bear numbers from 1 to 100; on the 8×8 field – from 1 to 64.
The field is a torus-shaped surface (doughnut) rolled out flat as shown in Fig. 1.
Squares along the field perimeter are auxiliary ones. They form an additional game field. They ‘duplicate’ squares of the main field on the other side. Fig. 2a shows a main square field (#5) and a corresponding additional square field.
Fig. 2b shows an example of a main field corner square (#8), which has three corresponding squares on the additional field.
There is a total of 4 squares of this kind on the main field: No. 1, 8, 57, 64, each having 3 ‘duplicate’ squares on the additional field (for 8×8 field).
All manipulations with chips are performed on the main field. If a chip is put onto an edge square (#4) of the main field, its ‘duplicate’ is put on the opposite side, on the additional field (Fig. 3a).
For side squares of the main field, one duplicate is put; for corner squares No. 1, 8, 57, 64, three additional duplicate chips for each one should be put (Fig. 3b).